Polishing materials are used to remove irregularities and to finish automobile painted surfaces. Operations including removing irregularities and surface finishing are also referred to as surface repairing. The term “irregularities (nibs)” refers to protruding parts of paint with a size of approximately 0.5 to 5 mm that are formed by dust in the painting environment or when balls of paint or the like collect on the paint nozzle and adhere as a nucleus to the paint surface. Paint repairing may be necessary not only for painting that is performed when repairing a chassis that has been damaged by an accident or the like, but also when painting new cars, where the occurrence of irregularities cannot be completely prevented.
Paint repairing generally includes three processes, namely removing irregularities, rough polishing, and finish polishing. Removing irregularities generally uses a polishing material with solid granules and an orbital sander. Irregularities can also be removed by a manual operation using a polishing material. Rough polishing and finish polishing are processes of removing fine scratches in the painted surface that occur when removing irregularities to the same appearance as an unpolished painted surface. During rough polishing, a combination of buffing and use of a polishing compound with a large polishing force is used to remove relatively large scratches in a short period of time, and during finish polishing, a combination of buffing and use of a polishing compound with a low polishing force is used to obtain a surface with the target appearance. The polishing tools that are generally used for rough polishing and finish polishing can be a rotary sander and a buffing sander, respectively. For mass appeal vehicles and the like which do not require a high quality finished surface, the rough polishing and finish polishing can be performed in a single process.
Patent document 1 (Japanese PCT (WO) Patent Application No. 2013-505145) discloses “a structured polishing article, comprising: a supporting body having first and second opposite facing main surfaces, and a molded polishing composite body which is an affixed structured polishing layer provided on the first main surface, wherein the molded polishing composite body comprises polishing particles and a non-ionic polyether surfactant dispersed in a cross-linked macromolecular binder, the average particle size of the polishing particles is less than 10 μm, the non-ionic polyether surfactant does not covalently bond with the cross-linked macromolecular binder, and the amount of non-ionic polyether surfactant is 2.5 to 3.5 weight %, based on the total weight of the molded polishing composite body.”
Patent document 2 (Japanese PCT (WO) Patent Application No. 2010-522092) discloses “a method of polishing a surface of an object to be processed, comprising: a step of preparing a polishing article attached onto a shaft of a drive tool that provides a polishing surface with attached polishing particles, a step of making contact between a surface of the object to be processed and the polishing surface of the polishing article, and a step of reciprocally rotating the polishing surface of the polishing article around the axis of rotation by reciprocally rotating the shaft of the drive tool, wherein the polishing surface of the polishing article is reciprocally rotated around the axis of rotation, while the surface of the object to be processed is polished by the polishing particles that are adhered to the polishing surface of the polishing article.”    Patent Document 1: Japanese PCT (WO) Patent Application No. 2013-505145    Patent Document 2: Japanese PCT (WO) Patent Application No. 2010-522092